The present invention relates to a method for manufacturing toothed gears, in particular for an adjustment device for reclining car seats.
Adjustment devices for reclining car seats typically comprise two sheet-metal sections or profiles independent of each other on both the left side as well as the right side, one of which is firmly connected to the seat or chassis and the other to the reclining back rest; the sheet-metal section is supported on an eccentric pin via interacting toothed discs or gears which are capable of being adjusted relative to each other by means of a motor-operated or hand-operated shaft for reclining the back rest. For this purpose, the toothed discs comprise, similarly to a planetary gearing, a pinion and hollow wheel with an unlike number of teeth so that the eccentric pin effects a radial-axial adjustment of the toothed discs.
A great problem in such systems involved the requirement for highest stability of the force-transmitting parts. Compliance with this requirement is made difficult by the significantly limited available space, apart from the necessity for an efficient, economical production. Thus, it is not possible simply to use thicker toothed discs to strengthen the torque-transmitting tooth root on the toothed disc, which in this connection-presents essentially the weak point.